Kawasaki disease (KD) diagnostic is based on clinical, laboratory and echocardiographic criteria. Coronary artery brightness is a criterion for diagnosis KD at the acute phase, but it is qualitative and subjective. Evaluation depends on the experience of individual echocardiographers.

Diagnostic value of quantitative evaluation of echogenicity of the coronary artery wall (CAW) in KD at the acute phase.

A retrospective case-control study was performed in Clermont-Ferrand university hospital. Echocardiograms of 0 to 18years old children between January 2012 to January 2014 was enrolled: 19 KD confirmed, 14 acute febrile illness and 34 apyretic children with congenital heart disease without coronary disease. Two dimensional echocardiography views were obtained using iE33 -Philips- with different probe. The value of echogenicity was evaluated in decibel on 2mm² Regions Of Interest (ROI) using QLAB software -Philips-. For each examination, precordial short axis cross-section at level of aortic valve, 3 ROI are placed at the coronary artery environment, 3 ROI at the proximal segment of the left or right CAW, and 3 ROI at the aorta. Quantitative evaluation of echogenicity of CAW was performed with the measurement differences between ROI. Intraobserver variability was 0.62.

Echogenicity of right CAW was significantly higher in the acute phase of KD than the other groups -P<0.001, area under curve ROC=0.8-. Also, it has been observed for left CAW -P=0.14-.

This first study highlights the interest of echogenicity quantitative measure of CAW for KD diagnostic. Echogenicity of CAW might be helpful in diagnostic for atypical or incomplete KD. The reproducibility has to be confirmed by a prospective study with more children suspected of KD.